A highly sensitive and anti-interference Bio-QDs biosensor for electrochemical detection calcium ion in plant tissue culture medium

Abstract

Metal ions are widely present in biological systems and participate in many critical biochemical processes. Resisting interfering ions and achieving specific detection at the biosensor present a significant challenge. Herein, we designed a highly sensitive and anti-interference Bio-QDs biosensor through the biosynthesis CdSe quantum dots (QDs) and the use of sodium hexametaphosphate (HMP) as a stabilizer (CdSe QD@HMP) for detecting the calcium ion (Ca²⁺) in plant tissue culture medium, which is known for its complexity. Because of the spatial hexahedron molecular structure and six interconnected tetrahedral P-O units of HMP increased the electronegativity and stability of CdSe, the CdSe QD@HMP easily captured Ca²⁺ in solution, resulting in a minimum detection limit of 0.377 µM for Ca²⁺ in the range of 1–300 μM. And HMP can also ensure that the detection process is not affected by negative ion interference. Additionally, the recovery rate of environmental samples was 96.40 % and 101.13 %, confirming the reliability and practicality of the prepared biosensors. Therefore, this strategy not only provides a green and safe pathway for synthesizing QDs, but also lays the foundation for the sensitive determination of metal cations in complex environment.